Developer: LinkedIn Corporation
Price: free Download on the App Store
LinkedIn, the leader in business social networking (at least in the US), has launched an iPhone version of its popular web service. Much like Facebook, the main function of this app is to provide a quick way to contact people that you have connected with online, but you don't have an up-to-date email address for.
Unlike Facebook, however, there is no chat - so your messages may not get answered immediately. Also, people tend to update their status fields infrequently on the service, so the "Feed" aspect of the app is for the most part useless.